Location of family farms

I've recently started trying to track down the farms of my great-great-grandparents in Norway. I've traced back our tree a bit but am having trouble understanding how to locate the farms. I've tried the maps but cant yet figure out the system. We're planning a trip to Norway and I'd like to find some areas to visit. Wondering if anyone can help with this. I am trying to locate Torp Nedre, Rakkestad http://digitalarkivet.arkivverket.no/en-gb/ft/person/pf01037996007284 and Strand http://da.digitalarkivet.no/ft/person/pf01036357000621 Any help or direction would be greatly appreciated.